1. Field of the Invention
The present invention generally relates to multi-purpose wheeled utility vehicles and, more particularly, is concerned with a utility cart in which each opposite side panel and wheel combination as a unit is erectible to a transport position without employment of end gates and foldable to a storage position over the bottom of the cart.
2. Description of the Prior Art
Lawn and garden work and general maintenance activities of the average homeowner frequently requires the use of a multipurpose manually-powered utility vehicle for hauling a variety of things. Over the years the ordinary wheelbarrow, with its shallow flared box supported by a single front wheel and two back legs, has served this function well. However, in the past decade or so there has been a trend toward use of the utility cart, with its deeper rectangular box supported by a pair of side wheels and back legs, as a substitute for or at least a supplement to the wheelbarrow.
Notwithstanding this growing recognition of the two-wheeled utility cart's superiority over the wheelbarrow as the more versatile hauling vehicle, the same major drawback that has plagued the wheelbarrow for years has dampen the acceptability of the utility cart as a viable alternative to the wheelbarrow. That drawback is the substantial amount of space required by the cart for storage when not in use. Most of the storage space in residential garages and yard sheds is occupied already by higher priority items such as the automobile, lawn mower, snow blower, bicycle, tricycle, and lawn and garden tools. Therefore, the homeowner's decision of whether to purchase a utility cart might very likely hinge on whether enough storage space remains unused.
One approach to easing the homeowner's dilemma is to make the utility cart collapsible or foldable so that when not in use it can be stored in a smaller space. Many different collapsible or foldable carts, trailers or other types of wheeled vehicles appear in the prior art. Representative of the prior patent art are the two-wheeled vehicles disclosed in Wissler U.S. Pat. No. 4,253,677, Rear et al U.S. Pat. No. 2,879,072, Kerr et al U.S. Pat. No. 2,469,506, Krna U.S. Pat. No. 1,128,333, Lyons U.S. Pat. No. 908,472, Boston U.S. Pat. No. 2,970,846, Seyforth U.S. Pat No. 2,767,996 and Quist U.S. Pat. No. 2,657,069.
Of all of the above prior art constructions, only the Wissler folding utility cart appears to have some promise as a solution to the storage space problem. However, even it seems to embody several limitations which make it less than an optimum solution to the dual problem of providing a construction which is foldable in a simple and easy way and to a size requiring minimum storage space, yet embodies sufficient structural integrity to ensure reliability during use and durability over time.
Specifically, one limitation in the Wissler utility cart is that the lower edges of its side wall panels are pivotally connected by hinges to opposite longitudinal side edges of its floor panel for folding each respective side panel and wheel combination as a unit between an erected vertical position and a stored prone position atop the floor panel. It will be observed that the hinges are exposed to the interior of the cart box formed by the side, front and rear wall panels and thus will tend to trap and accumulate dirt and other matter being hauled in the cart as well as moisture which will tend to corrode the hinge surfaces and adversely affect their operation and durability over time. Further, this particular location of the hinged connection inherently leaves space along each side of the floor panel between it and the side wall panels through which matter, such as dirt, sand and fertilizer, can escape as it is being loaded and hauled in the cart.
Still another limitation of the Wissler utility cart seems to be the arrangement used to mount the side wheels to the respective side wall panels, in particular, by a nut welded to the side wall panel which receives a wheel mounting bolt. If the cart is used to carry anything but the lightest loads, the high bending moment will over time likely cause fatigue of the threads and twisting of the bolt relative to the nut, ultimately resulting in inward toeing and contact of the wheels at their upper portions against the side wall panels.
Yet another limitation of the Wissler utility cart appears to be the arrangement by which the respective side wall panels and wheels mounted thereto are maintained in their erected vertical positions. The end wall panels must be installed at their respective front and rear positions between the side wall panels and locked in place by pins carried by the end panels. Thus, to erect the cart, each respective side wall panel and wheel must first be pivoted to the vertical position and then the respective end panels installed and locked in place. Not only is this procedure for erecting (or, conversely, for folding) the cart rather awkward to carry out, the arrangement for maintaining the cart in the erected position eliminates the possibility of using the cart without its end panels in place. This limits the cart to hauling things which will fit within its box.
A further limitation of the Wissler utility cart is that locking of the handle of the cart in sleeve sockets provided at the respective top edges of the side wall panels is only accomplished when the rear end panel is installed and locked in place. Thus, whenever the rear end panel is raised from its locking position, the handle becomes unlocked from the sockets.
Consequently, in view of the above-cited limitations present in the construction of the Wissler utility cart and their potentially adverse impact on the procedures required for converting the cart between storage and erected positions and on the structural integrity of the cart, it is readily apparent that a need still exists for an effective foldable utility cart construction which addresses both of the aforementioned problems. Such design should ensure that the materials and steps required to manufacture and assemble the cart are compatiable with existing techniques, that the structural integrity and durability of the cart are not compromised in reaching a design which facilitates easy foldable storage of the cart, and that the folding and erecting mechanism of the cart is operable in a simple, relatively automatic and reliable way.